Use of 21-Gene Recurrence Score May Be Linked to Chemotherapy Use and Health-Care Costs in Women With Breast Cancer
In a study using Pennsylvania Cancer Registry data reported in the Journal of Clinical Oncology, Epstein et al found that use of the 21-gene recurrence score (RS) assay was associated with lower use of chemotherapy and lower medical spending among patients younger than age 55 with early-stage breast cancer and higher use of chemotherapy and higher medical spending among those between the ages of 75 to 84.
Study Details
The study involved a retrospective cohort of women with early-stage breast cancer diagnosed from 2007 to 2010 who underwent initial surgical treatment. Data from 7,287 patients were merged with administrative claims from the 12-month periods before and after diagnosis. Overall, patient ages were < 55 years in 10%, 55 to 64 years in 10%, 65 to 74 years in 35%, 75 to 84 years in 34%, and ≥ 85 years in 11%.
The proportion of patients undergoing RS testing increased from 16% in 2007 to 28% in 2010 (P < .001). Patients receiving RS testing were younger, more likely to have Independence Blue Cross vs Medicare coverage, had fewer comorbidities, and were more likely to have stage I cancer. Overall, RS testing was performed in 39% of women aged < 55 years, 42% of those aged 55 to 64 years, 28% of those aged 65 to 74 years, 12% of those aged 75 to 84, and 1.4% (n = 11) of those aged ≥ 85 years (P < .001).
Association With Chemotherapy Use and Medical Costs
RS use vs nonuse was associated with significantly lower chemotherapy use among women aged < 55 years (41.5% vs 60.8%, P < .001), no significant difference in those aged 55 to 64 years (35.0% vs 41.0%, P = .13), no difference in those aged 65 to 74 years (21.3% vs 20.2%, P = .59), significantly greater use in those aged 75 to 84 years (14.4% vs 8.7%, P = .036), and significantly lower use among those aged ≥ 85 years (0% vs 2.3%, P < .001).
RS receipt was associated with lower adjusted 1-year mean medical spending (2010 dollars) among women aged < 55 years ($15,333 lower, P = .002), no significant difference among those aged 55 to 64 years ($1,733 lower, P = .70), no significant difference in those aged 65 to 74 years ($2,442 higher, P = .07), significantly higher spending in those aged 75 to 84 years ($3,489 higher, P = .009), and nonsignificantly higher spending in those aged ≥ 85 years ($9,788 higher, P = .06).
The investigators concluded: “RS receipt was associated with reduced use of adjuvant chemotherapy and lower health care spending among women with breast cancer who were younger than 55. Conversely, among women 75 and older, RS testing was associated with a modest increase in chemotherapy use and slightly higher spending. From a population perspective, the impact of RS testing on breast cancer treatment and health care costs is much greater in younger women.”
The study was supported by the Commonwealth of Pennsylvania–Department of Health.
Peter W. Groeneveld, MD, of University of Pennsylvania, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
